Field of Invention
The present invention relates to a lighting technology, and more particularly to a portable lighting device based on principle of thermoelectric power generation.
Description of Related Arts
In our social reality, lighting has already become a necessity for people's lives. At present, the majority of lighting devices are based on power generation from electricity. With the increasingly scarcity of the world's energy sources, the widespread application of electrical energy powered lighting will lead to the demanding supply of electrical energy sources, and especially during the summer peak period, the seriously shortage of electrical energy source may even affect the everyday lighting need of people. In addition, as more people are traveling and have great demand for portable lighting, people tend to use new energy sources other than electric energy source for lighting. Since thermoelectric power technology was invented, studies on lighting by thermoelectric power are never stopped. Thermoelectric power is a relatively easy way to providing lighting in the absence of electrical power. However, light apparatus in the existing technologies is far from practical application in the market. For examples, the thermoelectric LED lighting apparatus disclosed in the patent number 201220321281.7 mainly includes a lighting apparatus 1, thermoelectric power generation module 2 and a power storage device 3. As shown in FIG. 1 of the drawings, the thermoelectric power generation module 2 is a semiconductor thermoelectric power generation chip utilizing the temperature differences between the hot side and the cold side to generate power continuously for the lighting apparatus 1. This type of thermoelectric lighting apparatus in the existing technologies, in general, has the following major drawbacks: the thermoelectric power generation efficiency is low and the power generation capacity is low. This is caused by the relatively low temperature differences between the two sides of the thermoelectric power generation chip, which is the main constraint of the development in this technological area. In the existing technology, there is no solutions to solve the above problems, which is the solution to maintain a relatively large temperature differences between the two sides of the thermoelectric power generation chip. This leads to the light apparatus in the existing technologies fails to provide lighting to meet the actual application need. In addition, the instability of temperature differences also makes it difficult to provide a stable lighting output in actual use. At present, in this aspect, some improvement to ensuring temperature difference through large size radiators are emerged. However, this type of improvement will lead to the entire lighting apparatus to have a huge size and the cost effectiveness is even lower than lighting by using electricity directly. Accordingly, the subject of how to provide a non-electrical powered lighting devices with high power generation efficiency and convenient for carriage against these drawbacks in thermoelectric power generation has a very broad market prospects and which is the essential demand in this technological development.